Our heroes are approaching Chargestone Cave on the way to Mistralton City when they discover they have some uninvited guests—a group of Joltik clinging to their Electric-type Pokémon and draining their electricity! They head for the nearest Pokémon Center to heal Pikachu, Stunfisk, and Emolga, and bump into their friend Bianca, whose Xtransceiver’s battery has gone dead. Nurse Joy offers a quick recharge, and Bianca calls Professor Juniper, who has set up a base camp at Chargestone Cave, where she and her staff are doing research.
The researchers uncover an electrical abnormality in the cave, and when they go to investigate, Ash and friends discover that the Joltik and Galvantula who usually live in the cave and draw power from its electrically charged stones have been driven from their home for some reason—and that reason quickly becomes clear. It’s Team Rocket! They’ve blocked off an area of the cave and are stealing the electrically charged stones for Dr. Zager’s research.
Things get even worse when our heroes are surrounded by angry Galvantula outside the cave! Ash and friends attempt to make a run for it, but the Galvantula grab his Pikachu and Bianca’s Minccino, and their Trainers chase after them. When they catch up, they discover that Pikachu and Minccino are just fine—in fact, they’re helping to recharge the energy-starved Joltik and Galvantula by zapping them (gently) with Electric-type moves.
The whole group reconvenes to drive Team Rocket away from the cave, and during the battle, Cilan’s Dwebble evolves into a Crustle! The villains quickly flee, making off with a few charged boulders. With their departure, the Joltik and Galvantula are finally able to return home—and Bianca and Professor Juniper have some exciting plans for an Exchange Evolution as soon as they get back to the research camp!